Microbiological 11alpha-hydroxylation of 16alpha, 17alpha-epoxy pregnenes



United. Fatent BAWiYA-YQ Patented July 31, 1952 @iilice This invention relates to the hydroxylation of steroids. More particularly, it is concerned with a novel method or introducing hydroxyl groups into the ll-position 1n certain useful steroids of the pregnene series by means of microbiological fermentation. It also deals With the hydroxylated product.

The essential requirement for the ll-oxygen in steroids demonstrating anti-inflammatory activity, such as hydrocortisone and cortisone, is Well established. Such compounds are becoming increasingly important, either as therapeutic agents or/as intermediates in the preparation of other therapeutically useful steroids. Such compounds have been found useful, for example, as antiinflammatory agents in the treatment of arthritis, asthma, burns, bursitis, and the like, and also in the treatment of skin disorders and collagen diseases. As such, these compounds are used in combination with fillers, excipients, etc., in tablets, powders, pills, etc. They can also be used parenterally in a solution or in a suspension.

As indicated above, many of these steroids contain a hydroxyl group in the ll-position. According to the present invention, it has been found that this group can be introduced by fermentation in the presence of suitable fungi. Those fungi which have been found useful for" this purpose include, for example: Borryodiplodia theobromae, Didymocladium ternatum, MyrOtheCium roridum, Hormodendrum hordei, Hormodendrum pallidum, Fusarium solani and Penicillium ehrilichii. These fungi areirnore fully discussed below.

Typical steroids which can be usefully processed according to the present invention include, for example:

4-pregnene-2l-ol-3,20-dione-16a,l7e-epoxide; 4-pregnene-3,2O-dione-16a,17a-epoxide; and 5-pregnene-3fl-ol-20-one-16a,17a-epoxide.

lla-hydroxy-lfia, Hot-epoxy progesterone 160:, l7a-epoxy-progesterone When the starting material is an ester, such as the acetate, the acyl group also will be hydrolyzed as shown for example by the following illustration:

(131120006113 CHQOH C=O =0 or I .QQ or) 16oz, 17a-epoxy-DO O-2l-acetate lla-hydroxy-lfia, 17a-epoxy-D O O Wheren an ester, such as the 2l-acetate and the like, is desired asthe final product, it may be readily prepared from the reaction product by known methods. This may be done, for example, by reacting the product with an 'esterifying agent, such as acetic anhydride, or the like, in a suitable solvent such as pyridine or the like.

In carrying out the process of the present invention, the organism is cultivated aerobically in a suitable nutrient medium with the steroid which is to be hydroxylatedI During the growth of the organism under favorable conditions, the desired hydroxyl group is introduced into the steroid ring sructure. The exact mechanism of this hydroxylation is not wholly certain. It is thought to be caused by enzymes produced by the organism in the 7 process of growth.

A suitable nutrient medium contains a soluble source of carbon, nitrogen, and mineral elements. In general, the preparation of such media is well known and the practice of the present invention in this respect may follow such procedures.

In an illustrative preparation of inoculum, spores from a suitable culture on potato dextrose agar or the like are used to inoculate ml. of sterile medium in a 500 ml. Erlenmeyer flask. An illustrative medium of this type contains the following: 1% cornstarch, 1% cornsteep and 2% molasses, the whole being adjusted to about pH 7 with Ill-normal sodium hydroxide. This medium is used in the illustrative examples below. Inoculated medium is incubated at about 27 C. on a shaker for about 16 to 24 hours. Such inocula are used to inoculate larger batches of medium in seed bottles. Such bottle cultures, after further incubation, usually under conditions of aeration and stirring are used to inoculate large batches of medium in aerated, stirred fermenter tanks. This procedure is given as a typical illustration only. While it is used in the examples below, it may be varied if necessary or desirable in actual practice. For example, other media, media volumes, incubation periods, and temperatures may be used.

A good typical practice in fermenter tank procedure, one which also is used in the examples below, is illustrated in the following method. Medium is prepared in the tank, sterilized by heating and cooled to the temperature of the inoculant. The medium is then inoculated with from about one to about six percent of a vegetative inoculum prepared as above. The broth is then agitated with a stirrer at from about 100 to about 500 r.p.m., and aerated at the rate of about 0.5 to about 1.5 volumes of air per volume of broth. The actual values used will a vary within the approximate ranges shown, depending upon the volume, the shape of the tank, the stirrer and the like.

The inoculated tank or bottle is then maintained at the desired temperature, in the illustrative case about 27 (3., until the organism growth reaches about 0.3 g. per 100 ml., or more. The steroid substrate is then added, usually dissolved in methanol. A good practice is to use about 1 gm. of substrate per 60 ml. of methanol and to add a sufiicient amount to provide some 0.25 to 0.35 mg./ml. of broth. Agitation and aeration are continued until the substrate disappears. The culture broth is then harvested and the hydroxylated product isolated. Conversions of some to about 25 percent of the added substrates are readily produced.

The amount of steroid added as substrate to the fermentation may be varied as necessary or desirable. However, a good practice will ordinarily be to add on the order of about 0.05 to about 1.0 gram per liter of nutrient medium.

When using such steroid substrates in the fermentation, the products formed are the free steroids. The steroid substrates are generally added to the fermentation in solution or in finely-divided form. A preferred method is to dissolve the steroid in methanol or some other Watermiscible solvent and to add it to the fermentation medium at the desired stage in the process. Although the steroid may precipitate from solution when so added, it is dis-' EXAMPLES 1 AND 2 To illustrate the invention, inoculum and medium were prepared as hereinbefore discussed. Sterile medium in five gallon bottles was then inoculated, the culture grown, and the substrate added as shown in the following Table I. In Example 1, the fermenting organism was Didymocladium ternatum; in Example 2, Botryodiplodia theobromae. In both, the substrate added Was three grams of 16a,17ot-epoxy progesterone. The percent conversion data are expressed in Weight percent based on the Weight of substrate added.

TABLE I Example No 1 2 Agitator Speed 400 r.p.m. 400 r.p.m. Air flow rate (A) 0.6 0.5. Volume of Medium (liters) 12 12. Sterilization time 1 hr. at 120 1 hr. at 120 Inoculum 1.6% l 3%. Prefermentation time. 27 hrs 29 hrs. Conversion time 49 hr 26 hrs Initial nH' 7.3 7.0. Final pH 6.1 6.6. Conver ion 10% 21.2%

(A) =volurne of air per volume of medium per minute.

EXAMPLES 3 AND 4 To illustrate the practice on a larger scale, Examples 1 and 2 were repeated except that SO-gallon tanks were used and the added substrate was 16a,l7a-epoxy DOC- 21-acetate. In both examples, the fermentation organism was Myrothecium roridum. Details are shown in Table II.

Volume of ltiedium Sterilization time Inoculunn Prel'ermentation time- Conversion t me Initial pH. Final pH. 4.o Conversion 23.2%..

(A) =v0luu1e of air per volume of medium per minute.

EXAMPLE 5 Isolation of 11a-Hydroxy-ItSaJ7a-Epoxy-DOC About one hundred liters of Whole mash from culture Example 3 is filtered and the cake is washed with two 5 liter volumes of water. The combined filtrate and washings are extracted with three 28 liter portions of chloroform. The combined extracts (65 liters) are concentrated to about one liter, washed with three 250 ml. portions of 2% aqueous sodium bicarbonate, the sodium bicarbonate extracts being back extracted with 200 ml. of chloroform which is added to the main portion, and the latter is then washed twice with 250 ml. of Water. The resultant chloroform solution is dried with g. of sodium sulfate and filtered, the sodium sulfate being washed with two 100 ml. portions of chloroform and the washings returned to the main portion. The latter is then treated with 8 g. of activated carbon with stirring for about 15 minutes. The carbon is filtered off, washed with two 50 ml. portions of chloroform and the washings are added to the main portion.

The latter is concentrated under reduced pressure to about 50 ml. at which point 100 ml. ethyl acetate is gradually added, and the mixture concentrated to about 40 m1. and stored in the cold room overnight. The resultant crystals are filtered ofli, washed with five 10- ml. portions of ethyl acetate, slurrying the crystals with solvent and sucking very dry after each addition to remove yellow pigmented materials. The resultant crystals after drying weighed 4.24 grams.

Two grams of these crystals were chromatographed on a partition column prepared from 500 g. of diatomaceous earth moistened with the lower phase of a system composed of water-4 part; dioxane5 parts; cyclohexane- 4 parts (by volume). The column Was developed with the upper phase and the peak at 2.8 column retention volume, was collected and the solvent recovered. The residue was crystallized from ethyl acetate and recrystallized from methanol-ethyl acetate. The resultant crystals are of 11a,21-dihydroxy-16a,17u-epoxy-4-pregnene-3,20- dione.

EXAMPLE 6 Isolation of 11 a-Hydroxy-I 6a,] 7a-Epoxy-Progeszer0ne About 11 liters of whole mash, as produced in Example 1, is adjusted to about pH 5 and one kg. of diatomaceous earth is slurried therewith and stirred for 20 minutes, the slurry is filtered and the filtrate is extracted twice with 11 liters of ethyl acetate, the two extracts being pooled (volume about 21 liters). The pooled extract is washed with 2 liters of a 2% aqueous sodium bicarbonate solution and then concentrated under vacuum to about 1 liter. The crude product that separated is filtered ofi, yielding 7.5 grams. This is chromatographed on a diatomaceous earth partition column using a solvent mixture composed of 4 parts of petroleum ether, 2 parts of ethyl acetate, 3 parts of methanol and 2 parts of water to 'yield 273 mg. of substantially pure product. The product melts at 246247 C. and its infrared and ultraviolet spectra tracings are identical with those of a known sample of llm-hydroxy-l6a,17u-epoxyprogesterone.

5 EXAMPLE 7' Isolation of l 1 ot-Hydroxy-l 6 a,] 7a-Ep0xy-Progester0ne' To about 125 liters of mash produced according to the procedure of Example 1 and adjusted to about pH is added 3 kg. of diatomaceous earth. This mixture is slurried for 20 minutes and filtered, the cake being discarded. The filtrate is extracted twice with ethyl acetate, first with about 125 liters of solvent and second with about 65 liters. The pooled extract, about 140 liters, is washed with 30 liters of 1% aqueous sodium bicarbonate and concentrated under vacuum to about 1.5 liters, at which time 9.5 g. of crude solids separate. Of these solids, 4.2 g. are chromatographed as in the preceding example and 315 mg. of product melting at 244-245 C. is obtained. This product has identical infrared and ultraviolet spectra tracings as those of a known sample of lla-hydroxy-l6a,- 17ot-epoxy-progesterone.

EXAMPLES 8 AND 9 Preparation of 5 -Pregnene-3 5,1 1-Di0l-20-Orze-16o:,1 7a- Epoxide A sterile aqueous medium containing 2% commercial lactalbumin digest (Eda-min), 5% commercial dextrose (Cerelose), 6% by volume corn steep liquor was adjusted to about pH 7 with NaOH and ml. portions were then placed in 100 ml. test tubes. Each tube was then inoculated with 0.2 ml. of a 5 ml. aqueous suspension of spores and mycelium from an agar slant culture of either Fusarium solani (Example 8) or Myrothecium roridum (Example 9). So-inoculated tubes were placed on a reciprocating shaker at 28 C. for 66 hours. Then two mg. of epoxy pregnenolone dissolved in 0.2 ml. of 70% ethyl alcohol was aseptically added to each test tube culture and the tubes were replaced on the shaker. Some tubes were removed for steroid analysis after further incubation after periods of 24, 48 and 78 hours respectively. After being removed, the content of each culture tube was combined with 40 ml. of methylene dichloride in a 100 ml. bottle and subjected to shaking for 30 minutes at 28 C. Thereafter each so-treated mixture was allowed to separate into solvent and aqueous layers and the solvent layer was collected. Resultant methylene dichloride extracts were placed in a warm water bath and the solvent evaporated therefrom with the aid of an air jet. The resultant dried residues were submitted for paper strip chromatographic analysis. In each case, 5-pregnene-3,8,ll-diol20-onel6ot,l7a-epoxide (ll-hydroxy epoxy-pregnenolone) was produced. Treating' of several sample paper strips with a phthalic acid paraphenylenediamine test spray produced no colored spots, indicating no oxidation of epoxy-pregnenolone to epoxy-progesterone derivatives occurred.

While the substrates used in the foregoing discussion have previously been produced by other means, it is believed that the 5-pregnene-3B,1lot-diol-20-one-16a,17uepoxide is a new product. It is readily oxidized, via the known Appenauer oxidation with aluminum t-butoxide and acetone, to a product of known utility, i.e., 4-pregnene-l la-hydroxy-4-pregnene-3,20-dione-16a,17a-epoxide according to the reaction shown to the following diagram.

The several fungi disclosed and claimed herein are strains of known species disclosed in the following references:

Didymocladium ternatum (Bon) Sacc. (Sacca'rd'o, P. A., Sylloge fungorum omnium hucusque cognitorum, 4: 186-187,1886.)

Botryodiplodia theobromae Patouillard. Gilman, J. C., A Manual of Soil Fungi, p. 201, 2nd edit., Iowa State College Press, Ames, Iowa, 1957.

M yrothecium roridum Tode. (Ibid. p. 398.)

Hormodendrum hordei Bruhne. (Ibid. p. 330.)

Hormodendrum pallidum Oudemans. (Ibid. p. 330.)

Fusarium solani (Martins) Appeal and Wollenweber. (Gilman, J. C., A. Manual of Soil Fungi, pp. 372-377, 2nd edit., Iowa State College Press, Ames, Iowa, 1957.)

Penicillium ehrlichii Klebahn. (Raper, K. B., and Thom, C. A. Manual of the Peuicillia, pp. 146-148. Williams and Wilkins Co., Baltimore, 1949.)

Although, as shown above, these fungi are known, it is believed that their use in the above-described treatment of these particular substrates to produce ll-hydroxylated products according to this invention is new and novel.

We claim:

1. The process of ll-hydroxylating a steroid selected from the group consisting of 4-pregnene-21-ol-3,20-dionel6a,l7a-epoxide; 5-pregnene-3fl-ol-20-one-16a,l7a-epoxide; and 4-pregnene-3,20-dione-16,17a-epoxide, which comprises subjecting said steroid to the fermentative action of a hyd-roxylatin-g organism selected from the group consisting of Botryodiplodia theobromae, Didymocladium ternatum, Myrothecz'um roridum, Hormodendrum hordei and Hormodena'rum pallidum.

2. The process which comprises subjecting a steroid to the fermentative action of an organism selected from the group consisting of Botryodiplodia theob romae, Didymocladium ternatum, Myrothecium roridum, Hormodendrum hordei and Hormodendrum pallidum and recovering therefrom the corresponding ll-hydroxylated steroid.

3. The process which comprises the step of subjecting a steroid selected from the group consisting of 4-pregnene- 2l-ol-3,20-dione-l6u,17u-epoxide; 4-pregnene-3,20-dionel6a,l7a-epoxide l7a-epoxide to the ferrnentative action of an organism selected from the group consisting of Botryodiplodia lheobromae, Didymocladium ternatum, Myrothecium roridum, Hormodendrum hordei and Hormodendrum pallidum, and recovering therefrom the corresponding 1 l-hydroxylated steroid.

4. A process for the production of an ll-hydroxy steroid which comprises: contacting in an aqueous medium under submerged fermentation conditions, the corresponding non-ll-bydroxylated steroid to the hydroxylating action of an organism selected from the group consisting of Botryodiplodia theobromae, Didymocladium ternatum, Myrothecium roridum, Hormodendrum hordei and Hormodendrum pallidum.

5. A process according to claim 4 in which the steroid of the pregnene series to be hydroxylated is selected from the group consisting of 4-pregnene-2l-ol-3,20-dione-16a, l7a-epoxide; 4-pregnene-3,20-dione-l6a,l7a-epoxide; and 5-pregnene-3 B-ol-20-dione-l6a,l7a-epoxide.

6. A process which comprises: inoculating a nutrient medium containing assimilable carbon, nitrogen, and mineral salts with a hydroxylating agent selected from the group consisting of Botryodiplodia theobromae, Didymocladium ternatum, M yrothecium roridum, Hormodendrum hordei and Hormoa'endrum pallia'um; adding thereto a steroid, continuing the resultant fermentative action on the steroid until a substantial amount of corresponding ll-hydroxylated steroid of the 4-pregnene series has been produced, and recovering said product therefrom.

7. A process according to claim 6 in which the steroid to be hydroxy-lated is selected from the group consisting of 4-pregnene-2l-ol-3,20-dione-l6zx,17a-epoxide; 4-preg nene-3,20-dione-l6u,17ot-epoxide; and 5-pregnene-3B-ol- ZO-dlOIIe-L,170t-6POXld6.

and 5-pregnene-3B-ol-20-dione-16a,

8. A process for producing 11a-hydroxy-16a,17uepoxy progesterone which comprises contacting in an aqueous medium under submerged fermentation conditions 16u.,17a-epoxy progesterone and Dia'ymocladium ternatum and recovering said products therefrom.

9. A process for the production of lla-hydrOXY-lfia, 17a-epoxy progesterone which comprises contacting in an aqueous medium under submerged fermentation conditions 16a,17a-epoxy progesterone and Botryodiplodia theobromae and recovering said product therefrom.

10. A process for the production of 11oz,21-dihYdYOXy 16a,17u-epoxy-4-pregnene-3,20-dione which comprises contacting in an aqueous medium under submerged fermentation conditions 21-hydroXy'16a,17u-epoxy-4-pregnone-3,20-dione and Myrothecium roridum and recovering said product therefrom.

11. A method of preparing 5-pregnene-3B,11-dio1-20- one-l6a,l7a-epoxide which comprises contacting in an aqueous medium under submerged fermentation conditions 5-pregnene-3B-ol-20-one-16a,l7a-epoxide and Myrothecium rroridum and recovering said product therefrom.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Prescott et a1.: Industrial Microbiology, 3rd edition, McGraw-Hill Book Co., New York, 1959, pp. 755 to 756. 

1. THE PROCESS OF 11-HYDROXYLATING A STEROID SELECTED FROM THE GROUP CONSISTING OF 4-PREGNENE-21--OL-3,20-DIONE16A,17A-EPOXIDE; 5-PREGNENE-3B-OL-20-ONE-16A,17A-EPOXIDE; AND 4-PREEGNENE-3,20-DIONE-16,17A-EPOXIDE, WHICH COMPRISES SUBJECTING SAID STEROID TO THE FERMENTATIVE ACTION OF A HYDROXYLATING ORGANISM SELECTED FROM THE GROUP CONSISTING OF BOTRYODIPLODIA THEOBROMAE, DIDYMOCLADIUM TERNATUM, MYROTHECIUM RORIDUM, HOR,MODENDRUM HORDEI AND HORMODENDRUM PALLIDUM. 